martinayotte wrote:@AdrianM, For the CH_PD, I would never rely on weak internal PullUps, especially that Espressif is saying the following since the beginning in the HardwareUserGuide :
The enable pin CH_EN (pin 7) can also serve as a reset pin. If voltage for CH_EN pin is low, the
chipset ESP8266EX will power off. Note that this pin cannot be dangled.
Hi martinayotte, that reference is to CHIP_EN which is certainly not to be dangled
What I'm curious about is the 10K pull-up exclusively seen in Adafruit designs on GPIO16 aka CH_PD aka XPD_DCDC
I've been going by the Esspressif ESP8266EX Datashhet V4.4 which seems to map best with my ESP8266-12E parts, and it says:
3.1.1. General Purpose Input/Output Interface (GPIO) There are up to 17 GPIO pins. They can be assigned to various functions by the firmware. Each GPIO can be configured with internal pull-up (except XPD_DCDC, which is configured with internal pulldown)
SO if ever that pin were software configured for input, Adafruit boards would float that input mid-rail with no other connection to define it. Just trying to understand why they felt the need to do that